This invention relates generally to a hydraulic velocity damper and, more particularly, to a hydraulic velocity damper for use with a seat belt retractor system to control and limit the maximum velocity of seat belt webbing payout during loading.
Conventional load limiting devices are load dependant. These devices allow a seat belt webbing to payout at different velocity rates when various loads are applied to the device. Optimum performance of these conventional systems is targeted to a specifically sized occupant, i.e., an average sized occupant. However, when a smaller occupant, i.e., a small child, or a larger occupant, i.e., a large adult, is positioned within the conventional seat belt retractor system, less than optimum control of webbing payout results. Webbing payout is reduced for smaller occupants due to the relatively smaller force applied by the smaller occupant to the system during rapid deceleration. Conversely, the webbing payout is increased for larger occupants due to the relatively larger force applied by the larger occupant to the system. Thus, conventional load limiting devices fail to provide adequate control of seat belt payout for different sized occupants.